1. Field of the Invention
The present invention relates to hydromotive machine apparatus and to methods of making the same, such as turbine generator sets for hydroelectric power installations and pump systems used for irrigation or other pumped transport of large quantities of water. The hydromotive machines of the invention may comprise hydroelectric turbine generators or pumps employed to pump water for irrigation, water supply or other purposes.
2. Description of Related Art
The construction of hydromotive machine installations is usually carried out by installing hydromotive machines within a structure specifically designed and built for the purpose, usually a concrete structure such as a dam having one or more suitable spillways or water tunnels formed therein, or gates or locks specifically constructed for the purpose. Generally, a contractor builds a powerhouse downstream of a dam site and then assembles one or more turbine generator sets in place by installing the individual turbines and generator components in the powerhouse at a water course location that is below head water level, such as a discharge tunnel or tunnels under the dam.
Such construction techniques obviously entail the time and expense of building a powerhouse and providing a suitable water delivery conduit, but permit installation of one or more large turbine generator sets. Servicing of a large generator set or sets presents access problems however, and may require significant disassembly of the set. Delays in repair under these circumstances can be lengthy and require an extended shutdown period. Further, the size and weight of large turbine generator sets may be so great that transportation of the entire set is not possible. It is thus often necessary to disassemble the sets into subassemblies for handling and, if necessary, transport. Even lifting of the generator set or its components may be impossible without designing and building new support structures on which a crane may be positioned. Such disadvantages may be overcome by the utilization of smaller generator sets.
Permanent hydroelectric power installations utilizing turbine generator sets which are small enough to be lowered into and raised from their operating position for installation, manufacture and repair are known. For example, U.S. Pat. Nos. 4,143,990 and 4,207,015 to F. J. G. Atencio disclose different versions of moveable hydroelectric generator sets with a dam and U.S. Pat. No. 4,289,971 to Ueda discloses a turbine generator unit which may be raised or lowered for attachment to a fixed draft tube. Such small equipment is obviously limited in generating capacity. Although it is conventional in hydroelectric power installations to provide multiple electric generator sets at a single dam site, this technique is usually employed with large generator sets to justify the large construction costs needed for conventional housing of multiple units. This is so not only in conventional powerhouse installations, but also in tidal power generating installations such as the arrangement described in the article "Tidal Power Engineering In The U.S.S.R." by L. Bernstein appearing at pages 37-41 of Waterpower & Dam Construction, March, 1986.
U.S. Pat. No. 4,319,142 to H. A. Mayo, Jr. discloses an apparatus comprising a fabricated steel passageway comprising a single horizontal tier of three S-shaped water tubes joined together in a framework and positioned at the spillway of a dam beneath lifting hoists. Each water tube has a non-submersible turbine generator associated with it. Turbine runners positioned within the S-shaped water tubes are connected by horizontally extending shafts to generators or other machines mounted above the water course on a framework carried by the tube assembly. The entire unitary framework of water tubes with the machines mounted thereon may be raised by the hoists during flood conditions to prevent or reduce the impedance to water flow presented by the water tubes.